Maximum-voltage indicator



M. SULTZER MAXIMUM VOLTAGE INDICATOR Filed May 31, 1919 July 17, 1923.1,461,790

ATTORNEY Patenteduiy iv, was.

MORTON SULTZER, OF BROOKLYN, NEW YORK, ASSIGNOR TO AMERICAN: TELEPHONEAND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

MAXIMUM-VOLTAGE INDICATOR.

Application filed. May 31, 1919. Serial No. 301,002.

Toallwhomz'tmayconcern: 1

Be it known that I, MORTON SULTZER, residin at Brooklyn, in the countyof Kings and tate of New York, have invented cera tain Improvements inMaximum-Voltage Indicators, of which the following is a specification.

This invention relates to a device'for indicating the presencebfcurrents in an electrical circuit, and particularly for recording themagnitudes of the voltages producing such currents, when these currentsand voltages are of too short duration to be recorded by any of theordinary types of recording meters.

According. to the well known principles of electric induction, when twoelectrical circuits are located in close proximity to each other, achange or variation in the amount of current flowing in one of saidcircuits is apt to produce an electromotive force in the other circuit.Such induced voltages are apt to cause serious disturbances in theapparatus associated with such a circuit. A speci'fic instanceillustrating the above would be in the case of a telephone circuitstrung along the line of an electrified railroad with ground .return andexposed to the power circuits of such a system. Sudden increases ofcurrent in the power circuit due to short circuits or other troublewould induce a voltage between the telephone conductors and ground whichmight be sufiiciently high to break down protective devices, thus incertain circumstances producing currents in the telephone wiressufficiently high to permanently magnetize iron cores, or cause fires,or seriously disturb or .disarrange other delicate apparatus with whichthe 40 telephone line was equipped, or cause physical injury totelephone users. Accordingly in order to prevent disturbance anddestruction of apparatus associated with acircuit, it is desirable inadvance to have information as to the maximum voltages apt to be inducedon a circuitso inductively exposed to other electrical circuits.Furthermore,

as the most destructive and injurious of such voltages are of uncertainoccurrence, it 60 is not desirable to associate with such a circuitatype of voltage measuring device requiring'constant supervision, whilethe ordinary types of recording meters. cannot be used because they failto respond to impulses of duration as short as the duration of thesemost destructive voltages.

It is a general feature of this invention to provide a device forindicating and recording the voltages induced on an electrical circuit,such a device being capable of being permanently associated with such acircuit and requiring no supervision other than occasional inspection.Other and further fea tures of the invention will be clear from thefollowing description of the operation of the invention. I

The invention consists essentially of a plurality of individual unitsconnected in parallel between the electrical circuit and ground, or, ingeneral, between the two sides of the electrical circuit each unit beingadjusted to operate on a difierent and definite voltage, the diiferencein operating voltages being obtained by series resistances of differentvalues associated with each unit. The fundamental partsof each unit arerelays whichoperate on short current impulses, such as currents inducedon the electrical circuit. Associated with each unit and operatingwhenever the relays of that unit respond are visual and audiblesignaling means. Accordingly the number of units will operate wheneverrasurge of induced current is transmitted over the electrical circuit willserve as a means for measuring the voltage of such a current. I v

The invention may be more clearly understood from the accdmpanyingdrawing, in which is illustrated a circuit diagram embodying a preferredform of the arrangements of the invention. The line L may represent oneside of an electrical circuit exposed inductively to other electricalcircuits, and on which it is desired to measure the maximumvoltagesinduced thereon. For convenience the other side of this circuit may beshown as the ground. A plurality of individual units are shown connectedin parallel between the line L and ground by the conductors 1, 2 and 3.While only a specific number of individual units have been illustrated,it is understood that as many units as desired may be similarlyassociated with the line L. Included in the conductors 1, 2 and 3 arethe resistance elements R R R,, which are of different value, as, forpurposes of illustration, R might have a resistance of 5000 ohms, R, a

resistance of 10,000 ohms, R, a resistance of lays 5 and6 of each unit,are provided associated with the batteries 12 and 13. It is pointed outthat the current in the locking winding of one of the relays of the unitwill produce a magneto-motive force in the same direction as thatproduced by a given current in the operating winding of that relay,while the current in the locking Winding of the other relay will producea'niagneto motive force in the opposite direction to that due to thecurrent in the operating winding-of that relay. This is so that nomatter what may be the direction of the operating current through theoperating windings of the relays, the magneto-motive force due to thecurrent through one of the locking windings will always be in the samedirection as the magneto-motive force due to the operating current, andhence one of the relays will always become locked up. Vere it not forthis feature the direction of the current through the relay wndings, ifalternating, might be opposite to that of the direct current transmittedthrough the locking windings, with the result that opposing fluxes wouldbe setup in the relay cores which would serve to prevent the energizaton and locking up of. said relays. Associated with each of the lockingcircuits of the units is a condenser such as the con-' denser 21',='forthe purpose of completing the locking-up in case the current in theoperatmg winding should fall to avalue below that required for operationbefore the current in the locking winding has reached a value sutficientto lock th relay. At each of the units, and operating when one of therelays of a unit responds, is a signal lamp such as the lamps 9, 10 and11. The operation of any of the relays of the units will furthermoreoperate the pilot relay 30 and the buzzer apparatus 31, which provide anaudible s1gnal indicating the operation of the apparatus.

The invention may be more fully understood from the followingdescription of its operation:

If a difference in potential due to inductionfrom a neighbormg powercircuit exists between the line L and ground current will flow over thefollowingpath: from the line L, throughresistance R through one of thewmdmgs of relay 5 and through one of the windings of relay 6, to theconductor 4, to

nitude notwithstanding the resistance R the relays 5 and 6 will beoperated. Upon the operation of relay 5 the following locking circuitwill be closed about the relays 5 and 6 from ground and positive battery12, conductor 14, upper armature and contact of relay 5, conductors 15and 16, lower winding of relay 5, conductor 17, lower winding of relay6, conductor 18, resistance 19, conductor 20, winding of relay 30, tonegative battery 13, and ground. As has been for- -merly pointed out,due to the difference in direction of the two locking windings, theclosing of this circuit will lock up either the relay 5 or the relay 6;depending upon filament of signal lamp 9, conductor 26,

armature and lower contact of relay 6, con ductor 20, winding of relay30, to negative battery 13, and ground. If the relay 5 has been lockedup in place ofthe relay 6, this last mentioned circuit would have beencompleted" from the filament of signal lamp 9, over conductor 23, lowerarmature and contact of relay- 5, over conductor 25 to the conductor 20.The closing of this circuit will operate the signal lamp 9 which willindicate the operation of the unit associated therewith, therebyindicating that the current induced on the line L was of suflicientmagnitude to operate this unit. At the same time, the closing of eitherof the two last I If the voltage induced on the line L was i ofsufficient magnitude to overcome a resistance greater than R such, forexample, as the resistance R,, the second unit would be operated as wellas the first unit. This would be indicated by the operation of thesignal lamp 10 associated therewith. If the voltage of the inducedcurrent were of still greater magnitude, such that it would overcome notonly the resistance R, and the re- I sistance R but also theresistance Rthe third unit would be operated also. This would be indicated by theoperation of signal lamp 11 associated therewith. As the operation ofeach of the units is substantiallythe same as that already described forthe first unit, no further discussion thereof will be given.Accordingly, irom experivaried forms; without departin spirit oftheinvention as define J11 the ap mental data a relationship may "beestablished between the number and resistance of the units operatedandthe induced voltage needed .to operate such units, which relations ship.will serve as a means for. measuring such volt'age. It is pointedoutthat as many IlllltSfiS' desired may be associated with the appara-'tus, and that the deviceyis not limited to nerely the three unitsspecificall lllustrated.

, Furthermore, the devlce is not imited use with telephone circuitsalone, but is sultable for use with many typesof electrical circuits,

and=while the arrangements-have been herein specifically illustrated inaeform deemed desirable it is understood that they are capable ofembodiment in many and widely from the pended claims. 7

, What is claimed is:

j i 1. A voltage indicating device for a transmission line includin apluralityof resistance elements of di erent valuesconn'ected to saidline, individual units connected with' each of said resistance elements,each of said units including two relay means each having an actuatingwinding responsive to currents transmitted over the line and a lockingwinding, said locking windings being so related to 'said actuatingwindings that the to said line, individual units connected with, each ofsaid resistance elements, each of former windings will notmagneticallyop-- pose the latter windings of both relays at the same time, andsignaling means controlled by either of said relays.-

, 2. A voltage indicating device for a transunission line including aplurality of resistance elements of difierentvalues connected said unitsincluding two relay means each having an actuating winding-responsive tocurrents transmitted over the'line and a locking winding, the lockingwinding for one ofsaid relays-being so related to its actuating windingto lock up said relay when the current from said line is transmittedthrough said relays in one direction, the locking winding for the otherof said relays being related to its actuating winding to lock up saidrelay when the currrent from said line is transmitted through saidrelays in the other direction, and a signaling means operated'loy eitherof said relays.

3. A voltage indicating device for a transmission linejncluding aplurality of resist ance elements of different values connected to saidline, individual units connected with each of said resistance elements,each ofsaid units including two relay means each having an actuatingwinding responsive to currents transmitted over the line and a lockingwinding, said locking windings being So related to said actuatingwindings that the vidual relay units connected in parallel between saidline and the ground, each of said units being responsive to potentialsof different magnitudes between the line and the ground, signalingn eansindividual to and controlled by each unit, and-signaling means common toall ofsaid units and controlled by either one of said units.

5. A voltage indicating device for a' transmission line including aplurality of individual relay units, means for connecting said relayunits in parallel with the transmission line, each of said connectingmeans including a resistance element of different value whereby each ofsaid relay units will be responsive to potentials of different magniqtudes impressed 'on said line, and signaling means common to all of saidunits and controlledby either one of said units.

' In testimony whereof, I have signed my name to this specification this28th day of May, 1919.

MoR'roN SULTZER.

